The world has yet to figure out how to stop the relentless increase in global climate pollution. But one of the biggest obstacles to international climate action appears to be shifting.

The US Energy Information Agency (EIA) just reported that America's CO2 emissions plunged 3.8% in 2012. This is especially remarkable because their GDP grew by 2.8%. Economy growing -- emissions falling. America's CO2 emissions have now fallen in five of the last seven years since 2005. Last year the International Energy Agency (IEA) announced that between 2006 and 2011 the US had the largest reduction in climate pollution of all the world's countries or regions. They estimated the overall annual reduction at 430 million tonnes of CO2 (MtCO2). The main reasons were "lower oil use in the transport sector … and a substantial shift from coal to gas in the power sector." Now the US has followed that up by reducing CO2 pollution another 208 MtCO2 last year.

All told, US CO2 pollution was 709 MtCO2 lower than in 2005.

How big a deal is cutting 709 MtCO2 in annual emissions? It vastly exceeds all the CO2 emitted in Canada, the world's ninth largest climate polluting nation. From a US perspective it's equal to eliminating the combined CO2 emissions from seven western states: Washington, Oregon, California, Idaho, Montana, Utah and Nevada. That includes the economic giant of California that boasts one of the world's 12 largest economies, rivaling Canada's.